We could not reason out the way the robbers escaped，because we were unable to find any ________ of them.

One hundred percent _______ to your studies, though it can be lonely and no fun at all, will leave precious marks on your youth.

There being no witness on the spot, the police were delayed by the _____ of information about the crime.

He is __________ as a leader but he doesn’t have _________in teaching.

Bill was doing a lot of physical exercises to build up his ________.